AJP - Cell Physiology, Vol 263, Issue 1 C194-C199, Copyright © 1992 by American Physiological Society
Regulated expression of monocyte chemoattractant protein-1 in normal human osteoblastic cells
S. R. Williams, Y. Jiang, D. Cochran, G. Dorsam and D. T. Graves
Department of Oral Biology, Boston University Medical Center, Massachusetts 02118.
An influx of monocytes is observed in many different physiological and
pathophysiological states, including bone remodeling and injury. These
cells appear at early stages of bone formation and repair and persist
throughout the later stages. In experiments described here, unstimulated
normal human osteoblastic cells did not produce detectable levels of
monocyte chemotactic activity. However, interleukin-1 (IL-1)-stimulated
normal human osteoblastic cells produced a chemoattractant that is similar
to monocyte chemoattractant protein-1 (MCP-1) at the levels of mRNA
expression, protein production, and chemotactic activity. Northern blot
analysis indicates that IL-1 elicits a dose-dependent increase in MCP-1
mRNA in normal human osteoblastic cells. Two proteins of M(r) 9,000 and
M(r) 13,000 were specifically immunoprecipitated with MCP-1 antiserum from
IL-1-stimulated normal human osteoblastic cells. Monocyte chemotactic
activity from IL-1-treated cells was blocked by MCP-1 antiserum. These
studies establish that normal human osteoblastic cells can be induced to
produce monocyte chemoattractants and that this is accounted for by the
induced expression of MCP-1.
